Hm. I leveled a hunter a couple of months back. I think it took me a week and a half to get from 1-90. And it only gets harder from level 60. If you get the rest of the heirlooms and enchant them with the appropiate enchants, it'll take you no longer than four days.

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And by four days, I don't mean four days /played. It might be 25-35 hours /played or something if you do some clever questing, use Zygor's Guide or something like that.

For someone who is familiar and doesn't get bored of being forced to play in the early Goblin starting zones, easily 18-24 hours of gameplay over the course of maybe 2-5 days. For me, it would be 3 months later and my Goblin character would be staring at the town in a box area.

Edit: Glanced at a twitch stream where some dude got 1-90 in 17 hours played. Shouldn't be too hard. Good luck.

I looked at my 70 Warrior (different class, whatever) whom I dungeon spam has 1 day /played (questing is usually faster than that even).

I would just start a new Hunter (unless your lvl 66 has something like an item you can't get again that makes it warranted to move it). Levelling is sooo fast now with perks / boa's and levelling nerfs you will get there in no time.